You spawn near a forest. There's an entrance to some ravines right next to the spawn (see below). I didn't explore outside of the map so far, so I don't not what strange things might await you there.So far I have seen lots of jungle, snow and desert.

There are some mine shafts at x 332 y 41 z 309.A skeleton spawner at x 451 y 22 z 281 - nothing fancy in the chest though.I didn't find diamonds until now but there are a few chests around, one carrying 2 diamonds at x 525 y 24 z 216.

Seed Code: Tokyo Jungle

Spawn points

X: 197 / Y: 67 / Z: 208

Locations

X: -283 / Y: 71 / Z: 650

And what do we have here?A desert temple between a jungle and snow biom.

X: 202 / Y: 61 / Z: 179

There seem to be various ravines connecting, I only explored a little. Lots of coal and iron.The entrance is a few steps from the spawn - be careful! It's a small hole in the ground!